Valve



F. H. WELLS Dec. 19, 1933.

VALVE Filed July 22, 1931 2 Sheets-Sheet l INVENTOR. FPANKL w H WELL:

A TTORNEY.

F. H, WELLS Dec. 19, 1933.

VALVE Filed July 22, 1951 2 Sheets-Sheet 2 IllllflllI/lI/l!IIIIIIIIII -IIIIIIIIIIIIIIIIIIIIIIIIIIII/I FIG. 2

INVENTOR. FPA/V/(L //v H WELLS A TTOIRNEY.

Patented Dec. 19, 1933 vALvE Franklin 11. Wells, 'South Bend, Ind assignor to Bendix-Westinghouse Automotive Air Brake (3onipany,Piflsburgh, Pro, a corporation of man ' July 22, 1931'. Serial No, 552,415 roam. (or 230- 228) 2 This mvenison reiatesto fluid compressors, and mum partic'utwrly tea valve for controlling the or the fluid from the inflame stoflig e reservoir toque filled.

The ecmwmioml fluid compressor is operated at relatively high which necessarily imposes uponthe parts, and particularly the. valve mite considerable Fstress tending among other meets 'to rapidly depreciate the quality of thetmaterial. v Jr 7 It is,: therefore, the principal object of the inventionto provide a very simple and economical discharge valve construction wherein. the parts am-simiectedto a minimum of wear, witheuthemeva' :sa'mfie'hg theeifectiveness of valve in hem -extremely sensitive in its opening and closing movements. l

Afwther obieet of use invention is to provide a valve structure which is comparatively noise less in operation, it being the desire to eliminate to as great an extent as possible the undesirable valve pounding.

As inferred above, it is a further object to provide a structure wherein the possibility of breakage is reduced to a minimum.

Other objects of the invention including desirable details of construction and combinations of parts will be apparent from the following description of the illustrated embodiment of the invention disclosed in the accompanying drawings, in which:

Figure 1 is a central sectional view of a fluid.

compressor embodying my invention;

Figure 2 is a section through the compressor taken on line 2--2 of Figure 1 again showing in detail the discharge valve constituting the invention; and

Figure 3 is a fragmentary view of the valve structure showing the same enlarged and in detail.

As disclosed in the figures of the drawings, the valve mechanism constituting the invention may be incorporated in the conventional multicylinder air compressor comprising the usual casing 10 having compressor cylinders 12 containing pistons 14 connected by the usual connecting rods 16 to crank shaft 18. The air compressed by the pistons 14 in piston chambers 20 flows past a discharge valve 22 and into chamber 24, thence to the usual storage reservoir or other desired point of utilization. The cylinder head 26 which houses the discharge valve mechanism also houses the unloader mechanism 28.

The discharge valve mechanism, the details of which constitute my invention, preferably comprises a relatively thin high -car-bon steel disk valve member 34 of generally square shape with rounded corners, which member is normally firmly sea-ted upon a valve mat 36 form- 00 ineg anintegral flange par-t of the cylinder head 26. The rounded corners of the square disk 7 valve member are adapted to be guided by a bore 37 within the cylinder head 2t. 'I he disk member 34 is held in er'igage'ment with the seat 36 by arelativ'el'y light helical valve spring member 38 normally compressed between the outer face "of the v'aslve mernber-34 anda shoulder to on a valve plug 42, the latter being in threaded engagement with the cylinder head and .provid- 7-0 ing together with said the aforementioned fluid receiving chamber 24in unimpeded communioati'on with: the fluid reservoir. The disk vaivemelnber 34 is'pr'eferably guided during its movement by the walls of the bore 37 in the cylinder head.

Supplementing the valve spring '38 there is provided what is termed a valve cushion spring 44 normally compressed between the base 46 of the plug 42 and a valve guide member 48. The latter member is preferably fabricated as a steel stamping and is provided on its opposite side, faces with projections 52 and 50 acting respectively as stops for the disk valve member 34 and as a guide or end housing for the spring 44. The valve guide member 48 is guided in a second bore 54 in the cylinder head, which bore is concentric with bores 37 and valve disk 34. The valve guide member 48 normally rests against the shoulder formed at the lower end Q of bore 54, so that the projections 52 on its lower face are spaced by a predetermined amount from the upper face of the disk member 34;

In operation of the compressor the pistons 14 move upwardly and the pressure developed in the chambers 20 increases. When the pressure is sufficiently high to overcome the combined 7 load of the air pressure in chamber 24, the weight of the valve member 34 and the load of 90 the spring 38, the valve member 34-moves off its seat 36 and the compressed air is forced into the chamber 24 and thence into the reservoir. It will be noted, however, that the spring 38 is deliberately made very light which, together with the lightness of the disk 34, insures the desired very quick and sensitive movement of the valve. However, the force of the air from the compression chamber 20 imparts a relatively great speed of movement to the .5 9

valve disk 34, and inasmuch as the weak spring 38 is insufficient to dampen this movement some auxiliary means should be provided for appreciably reducing the velocity of the disk. If such an auxiliary damping means is not provided, the fast moving disk may be broken in its abrupt contact with the end of the plug 42 which acts as a stop for the valve member. It is with this object of damping the movement of the disk that the spring 44 and guide 48 are provided. The disk 34 in its upward movement contacts the projections 52 on the guide 48, the spring 44 picking up the load to increase the resistance to movement of the disk and lower its velocity. It is also to be noted that the springs 38 and 44 are additive in their effect of damping the movement of the disk valve member, and furthermore that their'damping function progressively increases as they are 44 can be sufliciently strong to return the member 34 toward its seat before a large diiference of pressure is developed between the chamber 24 and the cylinder space 20. This avoids the development of a high return velocity of member 34 and so reduces the likelihood that it will be broken by impact against the seat 36.

There is thus provided a Very simple and economical valve. construction reducing to a minimum the wear of the parts.

Such a construction also permits of a very light disk member 34, thus reducing to a minimum the inertia effect of this part at the relatively great high operating speed of the com pressor; likewise the construction disclosed reduces valve noise, this by virtue of the lack of pounding against the upper stop and lower valve seat.

. It is not my intention to limit the scope of my invention to the particular construction described and disclosed, nor otherwise than by the terms of the appended claim.

I claim: ,In a compressor having a cylinder and a piston therein together with a cylinder head having a chamber therein, said head having an opening communicating said chamber with said cylinder and being further provided with a member providing a movable stop, a discharge valve structure comprising a valve disk member normally seated to cut off the communication between the chamber and cylinder, a spring member normally compressed between a portion of said head and said valve member to retain the latter in position, a second. spring member surrounding'said first spring member, said second spring member being normally compressed between a portion of said head and the aforementioned stop, said stop being interposed between said head and valve. disk member, said first named springmember being yieldable to allow said valve disk to open sufiiciently to contact said stop irrespective of the speed of the compressor, and an abutment formed on said head for positively limiting further opening movement of said valve after the latter has contacted said stop andhasmoved the latter a predetermined distance against the resistance of said second spring member.

. FRANKLIN H. WELLS. 

